Devices for the transmission of torque while being rotated are known in the art. Such devices include the so-called Hooke universal joints and Rzeppa constant velocity joints, and other types of joints which make use of a single spring coil (for example, AU2002300495 to this same inventor) to join two rotatable shafts. Some known devices for transmitting torque over a joint involve complex linkage arrangements which can be prohibitively costly, for example the use of back-to-back universal joints linked together. In the known devices, the coupling joint can transfer torque between the shafts, although the performance of both of the constant velocity and universal joint types can suffer when placed under load because severe strain can be placed on the joint, and in particular on any joining pins. In the known prior art, the joints can only function over a limited range of relative operating angles in order to avoid damage.